#![allow(unused)] // 此行请放在该文件最开头

use core::arch::asm;
const SBI_SET_TIMER: usize = 0;
const SBI_CONSOLE_PUTCHAR: usize = 1;
const SBI_CONSOLE_GETCHAR: usize = 2;
const SBI_CLEAR_IPI: usize = 3;
const SBI_SEND_IPI: usize = 4;
const SBI_REMOTE_FENCE_I: usize = 5;
const SBI_REMOTE_SFENCE_VMA: usize = 6;
const SBI_REMOTE_SFENCE_VMA_ASID: usize = 7;
const SBI_SHUTDOWN: usize = 8;

// rust 和 SBI 的通讯
#[inline(always)]
fn sbi_call(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
    let mut ret;
    unsafe {
        asm!(
            "ecall",
            inlateout("x10") arg0 => ret, // 给 SBI 的参数0
            in("x11") arg1,     // 给 SBI 的参数1
            in("x12") arg2,     // 给 SBI 的参数1
            in("x17") which,    // 系统调用号
        );
    }
    ret
}

// 打印字符
pub fn console_putchar(c: usize) {
    sbi_call(SBI_CONSOLE_PUTCHAR, c, 0, 0);
}

// 关机
pub fn shutdown() -> ! {
    sbi_call(SBI_SHUTDOWN, 0, 0, 0);
    panic!("关机");
}
